Qhov zoo tshaj plaws corrosion kuj ntawm stainless hlau yog vim yog tsim ntawm ib tug tsis pom oxide zaj duab xis nyob rau saum npoo ntawm cov hlau, ua rau nws passive.Cov zaj duab xis passive no yog tsim los ntawm cov hlau reacting nrog oxygen thaum raug rau cov huab cua, los yog tshwm sim los ntawm kev sib cuag nrog lwm qhov chaw uas muaj oxygen.Yog tias cov yeeb yaj kiab passivation raug rhuav tshem, stainless hlau yuav txuas ntxiv mus.Feem ntau, cov zaj duab xis passivation tsuas yog rhuav tshem ntawm cov hlau nto thiab hauv cov cheeb tsam, thiab cov nyhuv ntawm corrosion yog tsim cov qhov me me los yog pits, uas ua rau irregularly faib me me pit-zoo li corrosion nyob rau saum npoo ntawm cov khoom.
Qhov tshwm sim ntawm pitting corrosion yuav yog vim muaj cov chloride ions ua ke nrog depolarizers.Lub pitting corrosion ntawm passive hlau xws li stainless hlau yog feem ntau tshwm sim los ntawm lub zos kev puas tsuaj ntawm tej yam aggressive anions mus rau passive zaj duab xis, tiv thaiv lub passive xeev nrog siab corrosion kuj.Feem ntau yuav tsum muaj oxidizing ib puag ncig, tab sis qhov no yog raws nraim qhov xwm txheej ntawm pitting corrosion tshwm sim.Qhov nruab nrab rau pitting corrosion yog muaj cov hlau hnyav xws li FE3+, Cu2+, Hg2+ hauv C1-, Br-, I-, Cl04-solutions lossis chloride daws ntawm Na +, Ca2 + alkali thiab alkaline ntiaj teb hlau ions uas muaj H2O2, O2, lwm.
Lub pitting tus nqi nce nrog nce kub.Piv txwv li, nyob rau hauv ib tug tov nrog ib tug concentration ntawm 4% -10% sodium chloride, qhov siab tshaj plaws poob vim pitting corrosion yog mus txog ntawm 90 ° C;rau ib qho tshuaj dilute ntau dua, qhov siab tshaj plaws tshwm sim ntawm qhov kub siab dua.
Post lub sij hawm: Feb-24-2023